(1) Field of the Invention
This invention relates to a process for preparing oxine impregnated-activated charcoal.
(2) Description of the Prior Art
Oxine (8-hydroxyquinoline) was first prepared about 100 years ago and it was introduced as an analytical reagent in 1926. Many investigations have been carried out on the reagent and it has proven to be one of the most valuable analytical reagents available for the separation and gravimetric, volumetric and photometric determination of many metals. Oxine forms stable and water-insoluble chelates with many metals.
The inventors of this invention have developed a method of removing radionucleides from the cooling and leakage-water from nuclear reactors using the properties of oxine as stated above. The principle of the method is simple and comprises adding an oxine into the cooling-water of the nuclear reactor or leakage-water therefrom to form water-insoluble and stable complexes of the radionucleides contained therein and adsorbing them on activated charcoal. Many kinds of operations can be employed in the method, for example an operation using activated charcoal on which oxine is adsorbed, a batchwise operation in which activated charcoal is added after addition of oxine, or a continuous operation using an activated charcoal column. However, the operation using activated charcoal on which an oxine is impregnated is recommended.
On the other hand, Japanese Patent Application Publication No. 8281/1972 discloses a method of removing heavy metals such as mercury, copper, chromium etc. from a water solution containing the heavy metals using an activated charcoal or silica gel on which oxine is adsorbed and carried.
The conventional method for preparing oxine impregnated activated charcoal comprises dissolving oxine in proper solvents and passing the solution through a column of activated charcoal or dipping the activated charcoal in the solution with stirring so that the activated charcoal adsorbs the solution and finally removing the solvents. However, the conventional method suffers from the defect that a large amount of organic solvent is required, because oxine is not readily soluble in water. In addition to that, organic solvents are particularly troublesome to handle and remove.
An easy and effective method for preparing an oxine impregnated-activated charcoal has been, therefore, long sought in the art.